It's not very often that the world changes in a significant way. Often change is rejected, feared, and denied. That's just part of human nature. But some people throughout history defied this nature - innovators in an established industry, and pioneers of entirely new ones. Steve Jobs was one such visionary, whose contributions to the computing and entertainment industry were nothing short of monumental. Others have shared his place at this prestigious level of human accomplishment, though not all of them have been celebrated as widely as Jobs has.

So here is a list of six people who changed the gaming world. A celebration, if you will, of human accomplishment:

Gary Gygax and Dave Arneson - Dungeons and Dragons

In 1973, Gary Gygax and Don Kaye founded Tactical Studio Rules, a gaming company that would later be renamed TSR Inc. In 1974, Gary Gygax and Dave Arneson created the world's first table-top role playing game: Dungeons and Dragons. TSR published the first version of this game that would go on to become wildly popular, and which led the way for many hundreds of variants over the last forty or so years. These two men not only changed the gaming industry, they created an entirely new industry. Millions of people today either have played, or still play this game in one form or another, and it doesn't look like Wizards of the Coast (who bought up TSR in 1997) has any intentions of dropping it.

Richard Garfield - Magic: The Gathering

He started out as a math geek, and then math professor for Whitman College. While studying, Richard was also developing a card game that he had fellow Penn State students play-test. Eventually, while searching for a publisher for his RoboRally game that he designed in 1985, he met Peter Atkinson, who was interested in Garfield's game, Magic: The Gathering. This game was first published in 1993 and quickly became a huge success, spawning many expansions, and paving the way for hundreds of other collectible card games that tried to match its success. Again, this was a case where one man created a product that spawned a whole new gaming industry. M:TG remains popular today, and is still the focus of tournaments all over the world where people compete to see who has most successfully mastered both deck building and game-play strategy.

Alexey Pajitnov - Tetris

In 1984, this Russian computer scientist developed the first version of the wildly popular line-forming game, Tetris. It was initially released by the Russian government, Pajitnov's employer at the time. He received no royalties for it until 1996 when he became the co-founder of The Tetris Company. Tetris currently holds numerous Guinness World Records, including the most ported video game of all time, having been ported in various ways to pretty much every game system that every existed. It lives on in every gamer's heart as one of the greatest puzzle games ever created. There is little doubt that despite the fact that Alexey Pajitnov is one of the industries most unsung heroes, his contributions to the gaming industry with just this game are undeniable.

John Carmack - Doom/id Software

If you grew up in the '80s and '90s, you have almost certainly played a game by this programmer and co-founder of id Software. While Carmack is credited for many games and innovations, the one game that he worked on that really changed gaming was Doom. This game was so innovative at the time that it set the bar for other first-person shooters, and set it high. It's estimated that Doom was played by more than ten million people within the first two years of its release, and has since had multiple sequels, each one raising the bar higher. Carmack's contributions to 3D gaming are astounding, having worked on some of the industries greatest games including Wolfenstein 3D, Quake, Rage, and of course Doom.

Shigeru Miyamoto - Nintendo

If you're a gamer, and you don't know this name, you should. The brilliant mind of Shigeru Miyamoto brought us some of the greatest video game franchises of all times. Such household names as Mario, Donkey Kong, The Legend of Zelda, Star Fox, F-Zero, and Pikmin all came from the imagination of this one man. We all grew up playing his games. Even today, the Mario franchise is going strong, and Miyamoto still works for Nintendo, dreaming up new ways of entertaining us. Nintendo has always been a trendsetter, but would they be where they are today without this man? Somehow I think not.

Miyamoto has been on Time Magazine's 100 Most Influential People of the Year in both 2007 and 2008 (when he topped the list), has been made a Chevalier (Knight) of the French Ordre des Arts et des Lettres, and has won countless awards and topped many other lists. Whenever there is talk of influential game design, this man's name comes first.

If I had to pick a name from this list that was more influential, and changed the world in a much more significant way than even the immortal Steve Jobs, it would be Shigeru Miyamoto.

There are so many other names that could be added to this list, but I wanted to keep this short. These six people alone have affected enough change in the world to last many lifetimes. Many of them started with just one idea, and grew it from there. None of them started out in life seeking to change the world, or create new industries, or shake up old ones. I'm sure that many of us wish we could be the next Gary Gygax, John Carmack, or Shigeru Miyamoto. The truth is, you could be. All it takes is one really good idea.